Growth-Promoting Activity of Bound Pantothenic Acid in the Rat

Abstract

Fractions of liver and yeast as well as certain synthetic derivatives of pantothenic acid were assayed microbiologically with Lactobacillus arabinosus and biologically by a rat growth method. The results of the rat assays ranged from 114 to 179% of the microbiological values for 1:20 liver powder, yeast, wheat bran and rice bran extracts. Relatively good agreement between the results of microbiological and rat growth assays was obtained for concentrates high in coenzyme A and also for a preparation of the Lactobacillus bulgaricus factor. Rats grew approximately as well on the diphosphate and the “γ” monophosphate of pantothenic acid as on the free acid. Panthenol showed no activity with L. arabinosus, but in a single assay was as active for rats as pantothenic acid itself. A series of fractions from yeast and liver showed essentially similar activities by rat assay as by microbiological assay. These substances were all high in bound pantothenic acid but low in coenzyme A. The inference, therefore, is that other naturally occurring bound forms of pantothenic acid are completely available to rats.